The New DT8100 Wireless Reciever & Wireless Buttons provide greater freedom for the user. By making the DT8100 Multi Lane Timer Wireless you can enjoy no more tangled lanes, less effort when setting up & using; and also less lane damage from exposure and people triping over lanes. Wireless DT8100 Multi Lane Timer is Great For: Swimming Events Run & Sprint Races School Carnivals Sport Events Features: Easily Mounted to bottom of standard DT8100 to convert it to Wireless Operated Includes 1 x Wireless Button Wireless Control up to 25M RF Remote Control - No Cords Required User Selectable Lane No. for Individual Wireless Buttons 16 Different RF Channels User-Adjustable to Another Channel to Avoid Interference with Nearby Units Requires 2 AAA batteries in each part. Replacement batteries available see code 1154661.